WO2015149859A1

WO2015149859A1 - Wash arm arrangement

Info

Publication number: WO2015149859A1
Application number: PCT/EP2014/056742
Authority: WO
Inventors: Marie MINDE
Original assignee: Electrolux Appliances Aktiebolag
Priority date: 2014-04-03
Filing date: 2014-04-03
Publication date: 2015-10-08

Abstract

A wash arm arrangement (1) for a dishwasher having a washing chamber comprising corners is provided. The wash arm arrangement (1) is adapted to reach into at least one of the corners. The wash arm arrangement (1) comprises a first wash arm (8) arranged to rotate around a first axis (11) and a second wash arm (9) rotatably arranged on the first wash arm (8) around a second axis (12), the second axis (12) being positioned a distance (d) from the first axis (11). The second wash arm (9) comprises a first outer portion (9.3) and a second outer portion (9.4). The first outer portion (9.3) and the second outer portion (9.4) are arranged with an obtuse angle (a) with respect to each other, measured at the second axis (12), in a plane substantially perpendicular to the second axis (12). The present invention also relates to a dishwasher comprising a wash arm arrangement (1).

Description

WASH ARM ARRANGEMENT

TECHNICAL FIELD

The present invention relates to a wash arm arrangement and a dishwasher.

BACKGROUND

Today's dishwashers are expected to perform high quality wash of dishes. Also, environmental concerns require an efficient use of water and energy during a wash cycle. The requirement of performing high quality wash of dish and the requirement of efficient use of water and energy during a wash cycle puts requirements of wash arm arrangements for dishwashers. The document US 5464482 A describes a wash arm construction including a primary wash arm having at least one secondary wash arm rotatably mounted to one of its ends. During rotation of the primary wash arm within a substantially square washing chamber, the secondary wash arm is rotated so as to extend into corners of the washing chamber during the rotation of the primary wash arm. Thereby, the spray action from the wash arm construction will have a better coverage than a wash arm arrangement as commonly known in the art, i.e. a single wash arm rotating around a single axis so as to create a generally circular spray pattern which does not extend into corners of the washing chamber during rotation. However, there is room for improvement of the wash arm arrangements described in the prior art, in particular with regard to coverage of the spray pattern.

SUMMARY

An object of the present invention is to provide an improved wash arm arrangement.

According to an aspect of the invention, the object is achieved by a wash arm

arrangement for a dishwasher having a washing chamber comprising corners, the wash arm arrangement being adapted to reach into at least one of the corners, the wash arm arrangement comprising;

- a first wash arm arranged to rotate around a first axis, a second wash arm rotatably arranged on the first wash arm around a second axis, the second axis being positioned a distance from the first axis, the second wash arm comprising a first elongated wash arm section and a second elongated wash arm section, wherein the first elongated wash arm section comprises a first outer portion and the second elongated wash arm section comprises a second outer portion, wherein the first outer portion and the second outer portion are provided with at least one spray nozzle respectively, and

a transmission arranged to transmit rotational movement between the first wash arm and the second wash arm,

wherein the first outer portion and the second outer portion are arranged with an obtuse angle a with respect to each other, measured at the second axis, in a plane substantially perpendicular to the second axis.

Since the first outer portion and the second outer portion are arranged with an obtuse angle with respect to each other, measured at the second axis, in a plane substantially perpendicular to the second axis, the spray nozzles provided at the first outer portion and the second outer portion will, during rotation of the first and second wash arms, have a better coverage in the washing chamber. Thereby, an improved wash arm arrangement is provided.

As a result, the above mentioned object is achieved.

Also, due to the first outer portion and the second outer portion being arranged with an obtuse angle with respect to each other, measured at the second axis, in a plane substantially perpendicular to the second axis, the spray nozzles provided at the first outer portion and the second outer portion will, during rotation of the first and second wash arms, have a better coverage in the washing chamber of a dishwasher having a substantially rectangular footprint and/or a substantially rectangular washing basket. Further, since a wash arm arrangement is provided having a better coverage in a washing chamber of a dishwasher, a dishwasher equipped with a wash arm

arrangement provided, can be configured such that it uses less water and energy during a wash cycle. According to some embodiments, the first elongated wash arm section and the second elongated wash arm section are arranged with the obtuse angle with respect to each other, in the plane substantially perpendicular to the second axis measured at the second axis.

According to some embodiments, the obtuse angle is selected from a range of 95-175 degrees, or preferably from a range of 135-165 degrees.

According to some embodiments, the transmission is arranged such that a rotation of the first wash arm in one revolution causes the second wash arm to rotate two revolutions in relation to the first wash arm.

According to some embodiments, the transmission is arranged such that a rotation of the first wash arm in a first direction causes the second wash arm to rotate in a second direction opposite to the first direction.

According to some embodiments, the first wash arm, the second wash arm, the distance, and the transmission are arranged such that, during rotation of the first wash arm and the second wash arm, the first outer portion and the second outer portion of the second wash arm will travel in a combined path substantially in the form of a polygon.

Since the first outer portion and the second outer portion of the second wash arm will travel in a combined path substantially in the form of a polygon, coverage in the washing chamber of a dishwasher is further improved and washing of dish being positioned in a corner of the dishwasher is facilitated

Further embodiments herein aim to provide a dishwasher comprising a wash arm arrangement according to some embodiments. Since the dishwasher comprises a wash arm arrangement according to some embodiments, the spray nozzles provided at the first outer portion and the second outer portion will, during rotation of the first and second wash arms, have a better coverage in the washing chamber of the dish washer.

Thereby, an improved wash arm arrangement is provided. Further, since better coverage is provided, the dishwasher can be arranged such that it requires less water and energy during a wash cycle. Thereby, a more environmental friendly dishwasher can be provided. According to some embodiments, the dishwasher comprises a washing chamber, the washing chamber comprising corners, wherein the washing chamber, the first wash arm, the second wash arm, the distance, and the transmission of the wash arm arrangement are arranged such that, during one revolution of the first wash arm within the washing chamber, the first outer portion of the first elongated wash arm section of the second wash arm is arranged to extend into two diagonally opposing corners of the washing chamber and the second outer portion of the second elongated wash arm section of the second wash arm is arranged to extend into two other diagonally opposing corners of the washing chamber. Since the first outer portion is arranged to extend into two diagonally opposing corners of the washing chamber and the second outer portion is arranged to extend into two other diagonally opposing corners of the washing chamber, coverage of the spray pattern is further improved.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description. Those skilled in the art will realize that the different features described may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention, as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which;

Fig. 1 illustrates a wash arm arrangement for a dishwasher according to some embodiments; and

Fig. 2a-2d illustrate a cross section of a dishwasher comprising a wash arm arrangement according to some embodiments DETAILED DESCRIPTION

The embodiments herein will now be described more fully with reference to the accompanying drawings. Like numbers refer to like elements throughout.

Fig. 1 illustrates a wash arm arrangement 1 for a dishwasher having a washing chamber comprising corners (not shown). The wash arm arrangement 1 is adapted to reach into at least one of the corners. According to some embodiments, the wash arm arrangement 1 is a wash arm arrangement 1 for a dishwasher having a washing chamber with a rectangular foot print, and/or a rectangular washing basket, where the washing chamber comprises four corners, and where the wash arm arrangement 1 is adapted to reach into each of the four corners during rotation within the washing chamber.

The wash arm arrangement 1 comprises a first wash arm 8 arranged to rotate around a first axis 1 1 . The first wash arm 8 may be provided with one or more spray nozzles 19. The wash arm arrangement 1 may further comprise a support arm 17 arranged to hold the first wash arm 8 at substantially a centre of a washing chamber of a dishwasher. The support arm 17 may comprise an inlet 21 connected to a washing liquid supply, such as a washing liquid pump (not show). The support arm 17 further comprises a hollow body in communication with said inlet 21 . The hollow body is in further communication with a washing liquid inlet of the first wash arm 8, in a region of the first axis 1 1 . The first wash arm 8 also comprises a hollow body which is in communication with the one or more spray nozzles 19 of the first wash arm 8. Thereby, washing liquid can be pumped from said washing liquid supply through the support arm 17 into the first wash arm 8 and out into a washing chamber of a dishwasher via the one or more spray nozzles 19. The one or more spray nozzles 19 may comprise one or more spray nozzles which is inclined in the sense that washing liquid being evacuated through said spray nozzle is evacuated in a direction opposite to an intended direction of rotation of the first wash arm 8. Thereby, washing liquid evacuated via said spray nozzles will result in a reaction force applying a torque onto said first wash arm which may cause it to rotate around the first axis 1 1 .

The wash arm arrangement 1 further comprises a second wash arm 9 rotatably arranged on the first wash arm 8 around a second axis 12. The second axis 12 is positioned a distance d from the first axis 1 1 . The second wash arm 9 comprises a first elongated wash arm section 9.1 and a second elongated wash arm section 9.2. The first elongated wash arm section 9.1 comprises a first outer portion 9.3 and the second elongated wash arm section 9.2 comprises a second outer portion 9.4. The first outer portion 9.3 and the second outer portion 9.4 are provided with at least one spray nozzle 13.1 , 13.2 respectively. The second wash arm 9 comprises a hollow body having an inlet in a region of the second axis 12, where said inlet is connected to an outlet of the hollow body of the first wash arm 8. Thereby, washing liquid can be pumped from said washing liquid supply through the support arm 17 into the first wash arm 8 and then into the second wash arm 9 and out into a washing chamber of a dishwasher via at least one spray nozzles 13.1 , 13.2 of the first outer portion 9.3 and the second outer portion 9.4 of the second wash arm 9. The second wash arm 9 may comprise further spray nozzles (not shown) which may be provided at locations of the second wash arm 9 other than the first or the second other portions 9.3, 9.4.

Similar to the first wash arm 8, the second wash arm 9 may comprise spray nozzles which is inclined in the sense that washing liquid being evacuated through such spray nozzles is evacuated in a direction opposite to an intended direction of rotation of the second wash arm 9. Thereby, washing liquid evacuated via such spray nozzles will result in a reaction force applying a torque onto said second wash arm 9 which thereby can cause, or contribute to, a rotation of the second wash arm 9 around the second axis 12.

The wash arm arrangement 1 further comprises a transmission 15.1 , 15.2, 15.3 arranged to transmit rotational movement between the first wash arm 8 and the second wash arm 9. In Fig. 1 , the transmission is illustrated as comprising a first gear 15.1 , a second gear 15.2 and a third gear 15.3. However, the transmission may comprise another type of transmission arranged to transmit rotational movement between the first wash arm 8 and the second wash arm 9. An example of such a transmission is a belt or a chain.

In the transmission 15.1 , 15.2, 15.3 according to the embodiments shown in Fig. 1 , the first gear 15.1 is connected to the support arm 17 and is stationary in relation thereto. The second gear 15.2 is arranged on the first wash arm 8 and comprises teeth which are arranged to intermesh with teeth of the first gear 15.1 . The third gear 15.3 is arranged on the first wash arm 1 at the second axis, i.e. the axis around which the second wash arm 9 is arranged to rotate. The third gear 15.3 comprises teeth which are arranged to intermesh with the teeth of the second gear 15.2. The third gear 15.3 is connected to the second wash arm 9.

Thereby, rotational movement will be transferred between the first wash arm 8 and the second wash arm 9. As previously mentioned, such rotational movement may be a consequence of washing liquid being evacuated through spray nozzles of the first and/or second spray arms 8, 9.

In the embodiments illustrated in Fig. 1 , the first gear 15.1 , and the second gear 15.2 each comprises twice as many teeth as the third gear 15.3 and an intermeshing circumference of the first gear 15.1 , and the second gear 15.2, are double the intermeshing circumference of the third gear 15.3. As a consequence, the second wash arm 9 will rotate two revolutions around the second axis, i.e. in relation to the first wash arm 8, when said first wash arm 8 rotates one revolution around the first axis 1 1 . As further discussed below, this may contribute to the outer portions 9.3 and 9.4 of the second wash arm 9 reaching into the corners of a washing chamber of a dishwasher during rotation of the wash arm arrangement 1 . The corners of the washing chamber referred to are the corners of a washing chamber in a plane substantially perpendicular to the second axis 12. Since the first gear 15.1 is connected to the support arm 17, rotation of the first wash arm 8 and the second wash arm 9 can be achieved in a predictable manner. That is, due a gear ratio of the transmission 15.1 , 15.2, 15.3 and the fact the first gear 15.1 is connected to the support arm 17 and thus stationary thereto, the second wash arm 9 will move in a predictable manner within the washing chamber of a dishwasher. Accordingly, the transmission 15.1 , 15.2, 15.3 according to these embodiments permits that an angular position of the second wash arm 9 can be known given an angular position of the first wash arm 8.

The first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, measured at the second axis, in a plane substantially perpendicular to the second axis 12. The expression obtuse angle is intended to encompass an angle which is between 90 and 180 degrees. However, according to some embodiments, the obtuse angle a is selected from a range of 95-175 degrees, or preferably from a range of 135-165 degrees.

Due to the obtuse angle a, the spray nozzles 13.1 , 13.2 provided at the first outer portion 9.3 and the second outer portion 9.4 will, during rotation of the first and second wash arms 8, 9 have a better coverage in the washing chamber. Further, in a washing chamber of a dishwasher having a substantially rectangular footprint and/or a substantially rectangular washing basket, the spray nozzles 13.1 , 13.2 will be able to have a spray pattern covering such a washing chamber and/or washing basket.

The obtuse angle a can be measured in the following ways;

In embodiments where the first outer portion 9.3 and the second outer portion 9.4 are provided with one spray nozzle 13.1 , 13.2 each, the obtuse angle a is measured as the angle between the spray nozzle 13.1 of the first outer portion 9.3 and the spray nozzle 13.2 of the second outer portion 9.4 measured at the second axis 12 in the plane substantially perpendicular to the second axis 12.

In embodiments where the first outer portion 9.3 and the second outer portion 9.4 are provided with more than one spray nozzle each, the obtuse angle a is measured between an average position of such more than one spray nozzles of the first outer portion 9.3 and an average position of such more than one spray nozzles of the second outer portion 9.4, measured at the second axis 12 in the plane substantially

perpendicular to the second axis 12.

As an alternative to both methods of measuring the obtuse angle a described above, the obtuse angle a can be measured between a centre line of the first outer portion 9.3 and a centre line of the second outer portion 9.4 measured at the second axis 12 in the plane substantially perpendicular to the second axis 12. The positions of such centre lines can be obtained by dividing a width of the first outer portion 9.3 and the second outer portion 9.4 with the number 2. Fig. 2a illustrates a cross section of a dishwasher 3 comprising a wash arm arrangement 1 according to some embodiments. The dishwasher 3 comprises a washing chamber 5 comprising four corners 7.1 , 7.2, 7.3, 7.4. The wash arm arrangement 1 is also illustrated in Fig. 2b-2d. Here, in order to improve brevity and clarity, some reference signs have been omitted. Likewise, in order to facilitate understanding of the working-principle of the wash arm arrangement 1 provided, some features of the wash arm arrangement 1 illustrated in Fig 2a-2d have been omitted. One of such feature is a transmission arranged to transmit rotational movement between the first wash arm 8 and the second wash arm 9. However, also the embodiments of the wash arm arrangement 1 shown in Fig 2a-2d comprise such a transmission, as any other embodiment described herein.

As illustrated in Fig 2a, the wash arm arrangement 1 comprises a first wash arm 8 arranged to rotate around a first axis 1 1 within the washing chamber 5 of a dishwasher 3. The wash arm arrangement 1 further comprises a second wash arm 9 rotatably arranged on the first wash arm 8 around a second axis 12. The second axis 12 is positioned a distance d from the first axis 1 1 . The second wash arm 9 comprises a first elongated wash arm section 9.1 and a second elongated wash arm section 9.2. The first elongated wash arm section 9.1 comprises a first outer portion 9.3 and the second elongated wash arm section 9.2 comprises a second outer portion 9.4. The first outer portion 9.3 and the second outer portion 9.4 are provided with at least one spray nozzle 13.1 , 13.2 respectively. The first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, measured at the second axis, in a plane substantially perpendicular to the second axis 12. The wash arm arrangement 1 is illustrated in Fig. 2a-2d in a sequence illustrating the first wash arm 1 undertaking one revolution within the washing chamber 5 of the dishwasher 3. The transmission (not shown) is arranged such that a rotation of the first wash arm 8 in one revolution causes the second wash arm 9 to rotate two revolutions in relation to the first wash arm 8. Also, the transmission is arranged such that a rotation of the first wash arm 8 in a first direction causes the second wash arm 9 to rotate in a second direction opposite to the first direction. As illustrated with arrows in Fig 2a-2d, the first wash arm 8 is illustrated as rotating clockwise and the second wash arm 9 is illustrated as rotating counter clockwise. During one revolution of the first wash arm 8 within the washing chamber, the second wash arm 9 will undertake two revolutions, in relation to the first arm 8. However, since the transmission is arranged such that the first wash arm 8 and the second wash arm 9 rotates in different directions, and since the second wash arm 9 is rotably arranged on the first wash arm 8, the second wash arm 9 will, during one revolution of the first wash arm 8 in the first direction, only undertake one revolution in relation to the washing chamber 5 in a direction opposite to the first direction.

In Fig. 2a, the first outer portion 9.3 of the first elongated wash arm section 9.1 extends into a first corner 7.1 of the washing chamber 5 of the dishwasher 3. Since first outer portion 9.3 is provided with at least one spray nozzle 13.1 , also this at least one spray nozzle 13.1 extends into in the first corner 7.1 of the washing chamber 5. Thereby, coverage of a spray pattern of the at least one spray nozzle 13.1 can be ensured.

In relation to the wash arm arrangement 1 illustrated in Fig 2a, the first wash arm illustrated in Fig 2b is illustrated as having rotated an angle which is smaller than 90 degrees. The dishwasher 3 illustrated in Fig. 2a-2d has a washing chamber 5 with a width 23 which is smaller than a depth 25 of the washing chamber. Accordingly, the washing chamber 5 of the dishwasher 3 has a substantially rectangular footprint. In Fig. 2b, the second outer portion 9.4 of the first elongated wash arm section extends into a second corner 7.2 of the washing chamber of the dishwasher. Since the second outer portion 9.4 is provided with at least one spray nozzle, also this at least one spray nozzle extends into in the second corner 7.2 of the washing chamber. Thereby, a rectangular spray pattern can be achieved and coverage of a spray pattern of the at least one spray nozzle within the washing chamber can be ensured.

Since the first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, measured at the second axis 12, in a plane substantially perpendicular to said second axis 12, the second outer portion 9.4 can extend into the second corner 7.2 of the washing chamber 5 even though the dishwasher 3 the first wash arm has rotated an angle which is smaller than 90 degrees. Thereby, the wash arm 1 arrangement will have a better spray coverage. Further, due to the obtuse angle a, during rotation of the first wash arm 8 and the second wash arm 9, the first outer portion 9.3 and the second outer portion 9.4 of the second wash arm 9 will travel in a combined path substantially in the form of a polygon having the form of a rectangle. That is, the wash arm arrangement 1 may be arranged such that the first outer portion 9.3 travels in a first elliptical path and the second outer portion 9.4 travels in a second elliptical path where the first elliptical path has a semi-major axis which is at an angle different from 90 degrees to a semi-major axis of the second elliptical path.

Thereby, the second wash arm 9 will travel in a combined path substantially in the form of a polygon having the form of a rectangle. As a result, coverage is further improved, especially in dishwashers having a rectangular footprint or a rectangular washing basket. Also, due to the obtuse angle a, the rotational pattern of the second wash arm is allowed and the first outer portion 9.3 and the second outer portion 9.4 of the second wash arm 9 will not hit inner walls of the washing chamber 5.

According to some embodiments, the size of the obtuse angle a is chosen on the basis of a rectangularity of a washing chamber 5 or washing basket of a dishwasher in which the wash arm arrangement 1 is intended to be arranged. The term rectangularity of a washing chamber 5 or washing basket is intended to encompass a ratio between a width 23 and a depth 25 of a washing chamber or a washing basket of a dishwasher.

In Fig. 2c, the first outer portion 9.3 of the first elongated wash arm section extends into a third corner 7.3 of the washing chamber of the dishwasher. Since first outer portion 9.3 is provided with at least one spray nozzle, also this at least one spray nozzle extends into in the third corner 7.3 of the washing chamber. In Fig. 2d, the second outer portion 9.4 of the first elongated wash arm section extends into a fourth corner 7.4 of the washing chamber of the dishwasher. Since second outer portion 9.4 is provided with at least one spray nozzle, also this at least one spray nozzle extends into in the fourth corner 7.4 of the washing chamber. Thereby, coverage of a spray pattern of the spray nozzles can be ensured.

Accordingly, as illustrated in Fig. 2a-2d, the washing chamber 5, the first wash arm 8, the second wash arm 9, the distance d, and the transmission of the wash arm arrangement 1 are arranged such that, during one revolution of the first wash arm 8 within the washing chamber 5, the first outer portion 9.3 of the first elongated wash arm section 9.1 of the second wash arm 9 is arranged to extend into two diagonally opposing corners 7.1 , 7.4 of the washing chamber 5 and the second outer portion 9.4 of the second elongated wash arm section 9.2 of the second wash arm 9 is arranged to extend into two other diagonally opposing corners 7.2, 7.3 of the washing chamber 5.

According to some embodiments, the first elongated wash arm section 9.1 and a second elongated wash arm section 9.2, are arranged with said obtuse angle a with respect to each other, in a plane substantially perpendicular to the second axis 12 measured at the second axis 12.

As an alternative, or in combination, according to some embodiments, the first elongated wash arm section 9.1 and/or the second elongated wash arm section 9.2 are curve shaped and/or angled such that the first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, measured at the second axis 12, in a plane substantially perpendicular to the second axis 12 Fig. 3 illustrates a cross section of a dishwasher 3 comprising a wash arm arrangement 1 according to some embodiments. The wash arm arrangement 1 comprises a first wash arm 8 arranged to rotate around a first axis 1 1 and a second wash arm 9 rotatably arranged on the first wash arm 8 around a second axis 12. The second axis 12 is positioned a distance d from the first axis 1 1 . The second wash arm 9 comprising a first elongated wash arm section 9.1 and a second elongated wash arm section 9.2. The first elongated wash arm section 9.1 comprises a first outer portion 9.3 and the second elongated wash arm section 9.2 comprises a second outer portion 9.4. The first outer portion 9.3 and the second outer portion 9.4 are provided with at least one spray nozzle respectively. The wash arm arrangement further comprises a transmission (not shown) arranged to transmit rotational movement between the first wash arm 8 and the second wash arm 9. The first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, measured at the second axis 12, in a plane substantially perpendicular to the second axis 12. As illustrated in Fig. 3, the first elongated wash arm section 9.1 is provided with an angle b, such that the first outer portion 9.3 and the second outer portion 9.4 is arranged with the obtuse angle a with respect to each other, measured at the second axis 12, in a plane substantially perpendicular to the second axis 12. Further, the second wash arm 9 may be provided in a different shape than the wash arm 9 illustrated in Fig. 1 , 2a-2d and 3. The second wash arm 9 may, for example, be curve- shaped, provided in an S-shape, or the like, as long as the first outer portion 9.3 and the second outer portion 9.4 are arranged with an obtuse angle a with respect to each other, in a plane substantially perpendicular to the second axis 12 measured at the second axis 12.

A dishwasher 3 provided may comprise two or more wash arm arrangements 1 .

Claims

1 . A wash arm arrangement (1 ) for a dishwasher (3) having a washing chamber (5) comprising corners (7.1 , 7.2, 7.3, 7.4), said wash arm arrangement (1 ) being adapted to reach into at least one of said corners (7.1 , 7.2, 7.3, 7.4), said wash arm arrangement (1 ) comprising;

- a first wash arm (8) arranged to rotate around a first axis (1 1 ),

- a second wash arm (9) rotatably arranged on said first wash arm (8) around a second axis (12), said second axis (12) being positioned a distance (d) from said first axis (1 1 ), said second wash arm (9) comprising a first elongated wash arm section (9.1 ) and a second elongated wash arm section (9.2), wherein said first elongated wash arm section (9.1 ) comprises a first outer portion (9.3) and said second elongated wash arm section (9.2) comprises a second outer portion (9.4), wherein said first outer portion (9.3) and said second outer portion (9.4) are provided with at least one spray nozzle (13.1 , 13.2) respectively, and

- a transmission (15.1 , 15.2, 15.3) arranged to transmit rotational movement

between said first wash arm (8) and said second wash arm (9),

characterized in that said first outer portion (9.3) and said second outer portion (9.4) are arranged with an obtuse angle (a) with respect to each other, measured at the second axis (12), in a plane substantially perpendicular to said second axis (12).

2. The arrangement (1 ) according to claim 1 , wherein said first elongated wash arm section (9.1 ) and said second elongated wash arm section (9.2) are arranged with said obtuse angle (a) with respect to each other, measured at the second axis (12), in the plane substantially perpendicular to said second axis (12).

3. The arrangement (1 ) according to any one of the claims 1 or 2, wherein said obtuse angle (a) is selected from a range of 95-175 degrees, or preferably from a range of 135-165 degrees.

4. The arrangement (1 ) according to any one of the preceding claims wherein said

transmission (15.1 , 15.2, 15.3) is arranged such that a rotation of said first wash arm (8) in one revolution causes said second wash arm (9) to rotate two revolutions in relation to said first wash arm (8). The arrangement (1 ) according to any one of the preceding claims wherein said transmission (15.1 , 15.2, 15.3) is arranged such that a rotation of said first wash arm (8) in a first direction causes said second wash arm (9) to rotate in a second direction opposite to said first direction.

The arrangement (1 ) according to any one of the preceding claims wherein said first wash arm (8), said second wash arm (9), said distance (d), and said transmission (15.1 , 15.2, 15.3) are arranged such that, during rotation of said first wash arm (8) and said second wash arm (9), the first outer portion (9.3) and said second outer portion (9.4) of the second wash arm (9) will travel in a combined path substantially in the form of a polygon.

A dishwasher (3) comprising a wash arm arrangement (1 ) according to any of the preceding claims.

The dishwasher (3) according to claim 7 comprising a washing chamber (5), said washing chamber (5) comprising corners (7.1 , 7.2, 7.3, 7.4), wherein said washing chamber (5), the first wash arm (8), the second wash arm (9), the distance (d), and the transmission (15.1 , 15.2, 15.3) of the wash arm arrangement (1 ) are arranged such that, during one revolution of said first wash arm (8) within said washing chamber (5), the first outer portion (9.3) of the first elongated wash arm section (9.1 ) of said second wash arm (9) is arranged to extend into two diagonally opposing corners (7.1 , 7.4) of said washing chamber (5) and the second outer portion (9.4) of the second elongated wash arm section (9.2) of said second wash arm (9) is arranged to extend into two other diagonally opposing corners (7.2, 7.3) of said washing chamber (5).